I own a recent tourer (Dawes Galaxy Plus) and would like to take it over some rougher stuff - muddy bridleways, gravel paths, that kind of thing. What holds me back is the tyres: 35-622 looks to be ...

I have seen more and more reference to the 650b (27.5") mtb wheel size. Whilst I don't see any need for a new standard, does anyone know of any benefit to have a 27.5" wheel over a 26" or 29"?
While ...